Microsatellite DNA markers for Lysiphlebus testaceipes

Microsatellite loci were isolated from the aphid parasitoid Lysiphlebus testaceipes (Hymenoptera: Braconidae). Ten loci were obtained from an enriched partial genomic library. Genetic diversity was analysed at seven of these loci and two natural populations, one on oleander and one on citrus. The observed number of alleles ranged from one to 17, and the observed heterozygosity ranged from 0.37 to 0.82. In both populations, no departure from Hardy–Weinberg equilibrium was detected except for one locus. The differentiation between the two populations was characterized by an F_ST of 0.09.     

Genomic architecture of alpha-amylase activity in mature rye grain relative to that of preharvest sprouting

Bi-directional selective genotyping (BSG) carried out on two opposite groups of F₉(541 × Ot1-3) recombinant inbred lines (RILs) with extremely low and extremely high alpha-amylase activities in mature (dry) grain of rye, followed by molecular mapping, revealed a complex system of selection-responsive loci. Three classes of loci controlling alpha-amylase activity were discerned, including four major AAD loci on chromosomes 3R (three loci) and 6RL (one locus) responding to both directions of the disruptive selection, 20 AAR loci on chromosomes 2RL (three loci), 3R (three loci), 4RS (two loci), 5RL (three loci), 6R (two loci) and 7R (seven loci) responding to selection for low alpha-amylase activity and 17 AAE loci on chromosomes 1RL (seven loci), 2RS (two loci), 3R (two loci), 5R (two loci) and 6RL (four loci) affected by selection for high alpha-amylase activity. The majority of the discerned AA loci also showed responsiveness to selection for preharvest sprouting (PHS). Two AAD loci on chromosome arm 3RL coincided with PHSD loci. The AAD locus on chromosome arm 3RS was independent from PHS, whereas that on chromosome 6RL belonged to the PHSR class. AAR-PHSR loci were found on chromosomes 4RS (one locus) and 5R (two loci) and AAE-PHSE loci were identified on chromosomes 1RL (one locus) and 5RL (one locus). Some PHSD loci represented the AAE (chromosomes 1RL, 3RS and 3RL) or AAR classes (chromosome 5RL). AAR and AAE loci not related to PHS were found on chromosomes 1RL, 2R, 3RS, 4R, 6RL and 7RL. On the other hand, several PHS loci (1RL, 3RS, 5RL, 6RS and 7RS) had no effect on alpha-amylase activity. Allele originating from the parental line 541 mapped in six AA loci on chromosomes 2R (two loci), 5R (three loci) and 7R (one locus) exerted opposite effects on PHS and alpha-amylase activity. Differences between the AA and PHS systems of loci may explain the weak correlation between these two traits observed among recombinant inbred lines. Strategies for the breeding of sprouting-resistant varieties with low alpha-amylase and high PHS resistance are discussed.     

Identification of one X‐linked and five autosomal microsatellite loci in Carabus violaceus (Coleoptera,Carabidae) and their applicability to related taxa

We characterize six microsatellite loci from the ground beetle Carabus violaceus. The polymorphism of the loci was assessed in 46 individuals from one population. The number of alleles ranges between three and eight, and the observed heterozygosities between 0.46 and 0.76. All males are homozygous for locus CVI08106CMPG, whereas most females are heterozygous. This suggests that this locus is situated on the X chromosome. Tests in eight different species of ground beetles showed that four loci could be amplified in C. coriaceus and one each in C. glabratus, C. nemoralis, C. problematicus and Abax parallelepipedus.     

A multiplex panel of microsatellite markers for widespread sub‐Saharan rodents of the genus Mastomys

We isolated and characterized 12 polymorphic microsatellite loci in the sub‐Saharan rodent Mastomys huberti. We tested cross‐species amplification of all these loci in three closely related Mastomys species: M. coucha, M. erythroleucus and M. natalensis. Multiplex panels comprising 11 loci were developed and their application to a set of individuals in each species allowed clear and easy characterization of allele sizes. Statistics from 31 M. huberti coming from one locality in Mali showed no deviation from Hardy–Weinberg equilibrium except for one locus, and no significant linkage disequilibria between loci.     

Novel microsatellite loci in the threatened European long-snouted seahorse (<Emphasis Type="Italic">Hippocampus guttulatus</Emphasis>) for genetic diversity and parentage analysis

The long-snouted seahorse Hippocampus guttulatus is one of the two European seahorse species. We describe the isolation of the first 12 microsatellite loci in this threatened species. These new markers were tested in non-invasive samples of 32 seahorses from NW Spain. The number of alleles ranged from 2 to 15 (mean: 6.3) and expected heterozygosity from 0.031 to 0.912 (mean: 0.500). All loci conformed to Hardy–Weinberg expectations and no genotypic disequilibrium was observed between any pair of loci. The theoretical exclusion probabilities for this set of loci, when no parental information exists or when one parent is known, were 0.973 and 0.998, respectively. This study indicates the usefulness of these novel loci for population analysis and kinship studies in Hippocampus guttulatus. Their potential application is extended to the other European seahorse species, since all loci were successfully cross-amplified in H. hippocampus.     

Genetic Divergence and Similarity of Introduced Populations of European Beaver (Castor fiber L., 1758) from Kirov and Novosibirsk Oblasts of Russia

Potential factors were analyzed that affected the formation of gene pools of two introduced beaver populations founded in the 1940s–1950s by releasing beavers from Voronezh oblast and Belarus into rivers of the Kirov and Novosibirsk oblasts. The populations from these two regions were shown to differ in four allozyme loci (Ahd-2, Gpi, Es-5, and Dia-2). Within Kirov oblast, the samples from three tributaries of the Vyatka River differed in three other loci (Ck-1, Gp-9, and Trf). It is suggested that these features of the allele distribution at these loci are explained by the history of the introduced populations, hybridization between beavers from Voronezh oblast and Belarus, and founder effect during the subsequent artificial and spontaneous migration. Generally, genetic differences between the populations in all studied loci were very small: D = 0.02 between populations from different regions and D = 0.01 between populations from the tributaries of third-order rivers of the Kirov oblast. At the same time, disequilibrium was detected for ten polymorphic loci in the combined sample from the populations of Kirov oblast, which indicates the existence of interpopulation heterogeneity at the level of local populations of fourth- and fifth-order rivers. The unexpected finding of a genetic similarity between one studied individual of Tuvinian beaver subspecies (Castor fiber tuvinicus) and C. f. orientoeuropeas was recorded.     

Isolation and characterization of microsatellite loci from the endangered highlands scrub hypericum (Hypericum cumulicola)

We report the isolation of 19 primer pairs for amplification of polymorphic microsatellite loci for Hypericum cumulicola. These markers were evaluated in 24 individuals from one population; two to four alleles were detected per locus, and observed heterozygosity ranged from 0 to 0.5. Two loci demonstrated significant heterozygote deficiencies, possibly due to null alleles, and significant linkage disequilibrium was found between six pairs of loci. The remaining microsatellite loci will help determine if genetic differentiation is responsible for life‐history differences between natural and anthropogenically disturbed populations of H. cumulicola.     

Polymorphic dinucleotide microsatellites in tongue sole (Cynoglossus semilaevis)

The tongue sole, Cynoglossus semilaevis, is a rare marine flatfish distributed in Chinese coastal waters. From a (GT)_n‐enriched genomic library, 57 microsatellites were isolated and characterized. Seventeen of these loci were polymorphic in a test population with alleles ranging from three to 13, and observed and expected heterozygosities from 0.1613 to 1.0000 and from 0.2126 to 0.8983, respectively. Five loci deviated from the Hardy–Weinberg equilibrium in the sampled population, and linkage disequilibrium between two loci was significant after applying Bonferroni correction. Three additional fish species assessed for cross‐species amplification revealed that only one locus was also polymorphic in one species. These polymorphic microsatellite loci should provide sufficient level of genetic diversity to evaluate the breeding strategy and investigate the fine‐scale population structure in C. semilaevis.     

Characteristics, linkage-map positions, and allelic differentiation of Sorghum bicolor (L.) Moench DNA simple-sequence repeats (SSRs)

Fifty one clones isolated from a size-fractionated genomic DNA library of Sorghum bicolor (L.) Moench, that had been probed with four radiolabeled di- and tri-nucleotide oligomers, were sequenced. Fifty of the clones contained one or more simple-sequence repeats (SSRs) [72% of which were (AG/TC) _n SSRs] and, following analysis of the clones, polymerase-chain-reaction primer sets that amplify 38 unique SSR loci were developed. Genotyping of the 38 loci in 18 sorghum accessions, including the parents of a recombinant inbred (RI) mapping population, revealed polymorphism at 36 of the loci among the 18 accessions and at 31 of the loci (not including null alleles at two loci) between the parents of the RI population. All of the latter 31 loci were mapped. The genotypes at 17-mapped SSR loci were assayed in 190 S. bicolor accessions in order to determine δ* _T , the estimated level of allelic differentiation (the estimated probability that two members of a population, chosen at random and without replacement, differ in allelic composition), at each of the loci. The mean δ* _T value determined for S. bicolor overall was 0.89, the range of mean δ* _T values for ten S. bicolor races was from 0.88 to 0.83, and the range of mean δ* _T values for ten working groups (= sub-races) of the race caudatum, with only two exceptions, was from 0.87 to 0.79. The lowest δ* _T values for six of the loci among the ten race-caudatum working groups ranged from 0.86 to 0.70; thus, the probability that different alleles will be present at one or more of these loci in two accessions chosen at random from a working group is > 0.996 when three of the loci are genotyped, and > 0.9999 when all six of the loci are genotyped. The results of this study confirm that most S. bicolor SSR loci are sufficiently polymorphic to be useful in marker- assisted selection programs and they indicate that the levels of polymorphism at some loci are high enough to allow the vast majority of S. bicolor accessions, even accessions within working groups, to be distinguished from one another by determining the genotypes at a small number, perhaps as few as a half-dozen, SSR loci. Received: 13 September 1999 / Accepted: 2 December 1999     

Eleven new microsatellite markers for the tropical sea urchin Tripneustes gratilla and cross‐amplification in Tripneustes ventricosa

We describe the isolation, characterization, and application of 11 polymorphic microsatellite loci from the tropical sea urchin Tripneustes gratilla. We genotyped a total of 73 individuals in three subpopulations (two in Hawaii, and one in the Philippines) and found between eight and 33 alleles per locus. We found significant heterozygote deficits within at least one subpopulation at seven out of 11 loci. We were successful at cross‐amplifying four loci in the congeneric Tripneustes ventricosus. When used appropriately, this set of loci will be useful for quantifying population structure in Tripneustes urchins across broad geographical ranges.     

Variable microsatellite loci isolated from the azure damselfly,Coenagrion puella (L.) (Zygoptera; Coenagrionidae)

We isolated and characterized 10 polymorphic microsatellite loci from the azure damselfly Coenagrion puella (Zygoptera; Coenagrionidae) as part of a study assessing reproductive success and genetic structure in an isolated population of this species. Levels of genetic diversity were assessed in 50 individuals collected from Queen Elizabeth Country Park, Hampshire, UK. The number of alleles per microsatellite loci ranged from three to 22 and the observed and expected heterozygosities varied between 0.26 and 0.84 and between 0.23 and 0.91, respectively. Two loci showed significant (P < 0.05) heterozygote deficits, likely because of null (non‐amplifying) alleles; one pair of loci was in linkage disequilibrium.     

Isolation of polymorphic microsatellite loci in the ponerine ant Ectatomma tuberculatum

We report the development of 11 microsatellite markers by an enrichment protocol in the ponerine ant Ectatomma tuberculatum. Polymorphism was explored in two colonies collected from Mexico and two colonies from Brazil. From the 11 loci which amplified, seven loci showed intracolonial polymorphism in Mexican colonies and only six loci were variable in populations from Brazil. Observed heterozygosity ranged from 0.18 to 0.84. The other five loci exhibited different alleles between Mexico and Brazil but geographical variability was not investigated further. Cross‐amplification was tested in another species of the same Tribe (Gnamptogenys striatula) and one locus was revealed to be polymorphic.     

EXPERIMENTAL STUDIES IN PONDEROSA PINE. I. RELATIONSHIP BETWEEN VARIATION IN PROTEINS AND MORPHOLOGY

Ponderosa pine from California (Pinus ponderosa var. ponderosa) were crossed to one another and also to individuals from the Rocky Mountains (P. p. var. scopulorum). All crosses involved a single mother and a single pollen donor. Patterns of inheritance of electrophoretically-detectable loci followed Mendelian expectations with one exception. Shikimate dehydrogenase showed unpredictable banding patterns in intervarietal crosses. Variability at these biochemical loci was compared to variability at 14 morphometric characters. The relationship between these two levels of variation is complex and permits only one generalization: variability at one level is not a good predictor of variability at the other level.     

Genetic structure among Thai populations of Aedes aegypti mosquitoes

Thirty‐one field populations of Aedes aegypti (L.) were compared using isozyme starch gel electrophoresis to characterize genetic variation between populations. Ae. aegypti were collected from seven provinces in Thailand. Thirty‐one isozyme encoding loci, including 19 polymorphic loci, were characterized. Only small levels of genetic differentiation were observed among the 31 district populations in the seven provinces. Isolation by distance among populations from the seven provinces showed no correlation between genetic variation and geographical distance.     

Isolation and characterization of microsatellite markers in the caddisfly Drusus discolor (Trichoptera: Limnephilidae)

We describe the development of and amplification conditions for microsatellite primers isolated from the caddisfly Drusus discolor. Eight polymorphic microsatellite loci were developed and screened for variability using 37 individuals from two populations from central Europe. The primers yielded an average of 8.6 alleles per loci. No linkage disequilibrium between loci was detected, while three loci showed deviations from Hardy–Weinberg equilibrium in one of the two tested populations.     

Recombination mapping of some chromosome 1A-, 1B-, 1D- and 6B-controlled gliadins and low-molecular-weight glutenin subunits in common wheat

 Inheritance of low-molecular-weight glutenin subunits (LMW GS) and gliadins was studied in the segregating progeny from several crosses between common wheat genotypes. The occurrence of a few recombinants in the F₂ grains of the cross Skorospelka Uluchshennaya×Kharkovskaya 6 could be accounted for by assuming that the short arm of chromosome 1D contains two tightly linked loci each coding for at least one gliadin plus one C-type LMW GS. These loci were found to recombine at a frequency of about 2%, and to be linked to the Glu-D3 locus coding for B-type LMW GS. Some proteins showing biochemical characteristics of D-type or C-type LMW GS were found to be encoded by the Gli-B1 and Gli-B2 loci, respectively. Strongly stained B-type LMW GS in cvs Skorospelka Uluchshennaya and Richelle were assigned to the Glu-B3 locus, but recombination between this locus and Gli-B1 was not found. Analogously, in the cross Bezostaya 1×Anda, no recombination was found between Gli-A1 and Glu-A3, suggesting the maximum genetic distance between these loci to be 0.97% (P=0.05). A B-type LMW GS in cv Kharkovskaya 6 was assigned to the Glu-B2 locus, with about 25% recombination from the Gli-B1 locus. The present results suggested that alleles at Gli loci may relate to dough quality and serve as genetic markers of certain LMW GS affecting breadmaking quality. Received: 9 July 1996/Accepted: 15 November 1996     

New microsatellite loci confirm hybrid origin,parthenogenetic inheritance,and mitotic gene conversion in the gynogenetic Amazon molly (Poecilia formosa)

We describe the first microsatellite loci for the gynogenetic Amazon molly, Poecilia formosa, an all‐female species arisen through hybridization of the bisexual species Poecilia mexicana and Poecilia latipinna. The loci showed one to six alleles and an expected heterozygosity between zero and 0.75. As expected with parthenogenetic inheritance, most loci were either constantly homozygous (five loci) or constantly heterozygous (eight loci). For six loci, both heterozygotes and homozygotes occurred. This and the fact that some loci only showed alleles of one of the ancestral species could indicate genome homogenization through mitotic gene conversion. Our new loci conformed to the hybrid origin of Amazon molly and are also applicable to both ancestral bisexual species.     

Genetic linkage relationships of eight enzyme/electromorph loci in Anopheles minimus

Two laboratory stocks of Anopheles minimus, each fixed for variant electromorphs of esterases, aspartate aminotransferase, hydroxyacid dehydrogenase, phosphogluconate dehydrogenase, mannose phosphate isomerase and glycerol dehydrogenase were used to assess linkage relationships between presumed gene loci controlling this variation. The two F₁, which had been obtained from crossing the stocks, were backcrossed to a parental stock. Three loci controlled the esterases and one locus each of the other enzymes. Mpi is sex-linked. The rest are autosomal and suggested relationships are: Pgd 2.3% recombination from Aat and unlinked to any other loci; Est-1-33.8%-Est-3-31.5%-Est-2-21.0%-Had. Gcd is unlinked to any other locus.There was evidence of strong interaction between the X chromosome of one stock and autosomes of the other in which individuals bearing the X chromosome of the one suffered relatively greater mortality and had delayed development with respect to other genotypic classes.     

Unidirectional gene conversions in the chloroplast of Chlamydomonas interspecific hybrids

Summary With the goal of studying directly the inheritance and recombination of physically mapped markers on the chloroplast genome, we have recently identified and localized physical differences between the chloroplast DNAs (cpDNAs) of the interfertile algae Chlamydomonas eugametos and C. moewusii. Here we report the inheritance patterns of 24 polymorphic loci mapping throughout the chloroplast genome in hybrids recovered from reciprocal crosses between the two algae. Most polymorphic loci were found to be inherited mainly from the mt ⁺ parent, with no apparent preference for one or the other parental alternatives in reciprocal crosses. Virtually all hybrids, however, inherited exclusively the long alleles of three loci; i.e. an intron in the large subunit ribosomal RNA gene of C. eugametos, a 21 kbp sequence addition in the inverted repeat of the C. moewusii cpDNA and a 5.8 kbp sequence addition in one of the single-copy regions of C. moewusii cpDNA. As these alleles are derived from opposite parental strains, their unidirectional inheritance in hybrids results necessarily from interspecific recombination of cpDNA molecules. We propose that gene conversion events led to the spreading of the long alleles of the three loci.